4(N,N-dimethylamino) benzaldehyde nicotinic hydrazone as corrosion inhibitor for mild steel in 1 M HCl solution: An experimental and theoretical study

4(N,N-dimethylamino) benzaldehyde nicotinic acid hydrazone is prepared and investigated as corrosion inhibitor for mild steel in 1 M HCl using weight loss, electrochemical method, quantum chemical calculation, FE-SEM and AFM method. The inhibition efficiency increases with increasing inhibitor concentration. The polarisation study indicates that it acts as a mixed type corrosion inhibitor. The adsorption of inhibitor is spontaneous and obeys the Langmuir's adsorption isotherm. The FE-SEM images and AFM images of mild steel support strong adsorption and high inhibition efficiency of the inhibitor. Quantum chemical parameters are also in agreement with experimental obtained efficiency. (C) 2016 Elsevier B.V. All rights reserved.